Question

If the length of a minute hand of a wall clock is 6 cm, then the area swept by it in 20 minutes is

Answer 1

Answer:

The answer is 37.68 cm².

Step-by-step explanation:

Let clock represent a circle

and minute hand represent radius.

For a circle,

$r = 6cm$

angular displacement in one minute = 6°

Therefore,

angular displacement in 20 min = 120° = t

Therefore,

area swept

$= \frac{t}{360} \times \pi {r}^{2}$

$= \frac{120}{360} \times 3.14 \times {6}^{2}$

$= \frac{1}{3} \times 3.14 \times 36$

$= 3.14 \times 12$

$= 37.68 \: cm {}^{2}$